Ladder-locking device.



M. E. HOWELLS.

LADDER LOCKING DEVICE.

APPUCATION FILED SEPT- 1915- patented May 16,

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M. E. HOWELLS.

LADDER LOCKING DEVICE.

APPLICATION FILED SEPT-7,1915- 1 183 565. Patented May16, 1916.

2 SHEETSSHEET 2.

THE COLUMBIA PLANOCIRAPH 520-, WASHINGTON, D. c,

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LADDER-LOCKING DEVICE.

Application filed September 7, 1915.

To all whom 2'25 may concern Be it known that I, MORGAN EDWIN How- ELLS, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Ladder- Locking Devices; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertain to make and use the same.

This invention relates to new and useful improvements in ladders, and more particularly to that class of rolling ladders, which are adapted to move on a runway or track, and are used in stores, ware-houses, etc., and the primary object of this invention is to provide an improved ladder of this type which is provided with a brake, that is normally applied, so that the ladder will be firmly and securely held in any desired position.

Another object of this invention is to provide an improved ladder of this character embodying the brake mechanism that may be easily and simply operated to retract the brake when it is desired to move the ladder to a different position, and said mechanism having means for automatically applying the brake, as soon as the operating lever is released.

A further. object of the invention is to provide a device of this character which is simple and durable in construction, inexpensive to manufacture, and one which will be very eflicient in operation.

With these and numerous other objects in view my invention consists of the novel features of construction, combination and arrangement of parts which will be hereinafter referred to and more particularly pointed out in the specification and claims. 7 In the accompanying drawings: Figure 1 is a side elevation of a portion of a ladder and the track, showing my improved brake applied thereto: Fig. 2 is a central vertical transverse section taken on the line 2-2 of Fig. 1; Fig. 3 is a central vertical longitudinal section of my improved brake mechanism, and Fig. 4 is a section taken on the line 4-4 of Fig. 3.

In describing my invention I shall refer to the drawings in which similar reference characters designate corresponding parts throughout the several views, and in which the numeral 1 designates a ladder of the or- Specification of Letters Patent.

Patented May 16, 1916.

Serial No. 49,302.

dinary type such as used for the purpose for which this device is used, having a rung or step 2, and the said ladder having at the top thereof, some means whereby the same is movably mounted on a track 8, by means of a pulley 4. The means by which this pulley 4 is connected to the side bars 5 of the ladder is not shown, as it may be of any preferred form of bracket, such as is commonly used in supporting ladders of this character. This ladder 1 is provided at its lower end with the usual type of rollers, so that the same may be easily rolled along the floor, to different desired positions. This ladder may be constructed of any preferred form or shape, that embodies the general characteristics as shown in the drawing, that is having a track, to which the improved brake may be attached.

Secured beneath one of the steps 2 of the ladder 1, is a casing 6 which projects from the said step or rung, and extends longitudinally with respect to, and directly beneath the track 3. This casing 6 is adapted to support the brake mechanism'of this invention as will be hereinafter more fully set forth. Secured to the side bar 5 of the ladder 1 are a pair of bracket members 7 and 8, which are adapted to slidably support therein, an operating rod 9. This operating rod 9 has secured thereon between the brackets 7 and v8 a handle 10 so the same may be easily grasped for the purpose of moving it to operate the brake. The rod 9 has its portion that is normally positioned between the apertured ears 11 andv 12 of the bracket 7 surrounded by a coiled spring 18, which spring has its upper end bearing against a collar 14 that is securely attached to the said rod. It will be obvious that upon any down ward movement of the rod the coiled spring 13 will be contracted, owing to the fact that the collar 14 will compress the same, and upon releasing the operating rod 9 the same will be moved upwardly to its normal position by the expansion of the said spring.

Projecting laterally from the casing 6, and extending to a point adjacent the side bar 5 of the ladder 1, is a rockshaft 15, which is supported against the side bar 5 by means ofa bracket 16 in which the free end of the shaft is positioned. This shaft 15 has positioned thereon adjacent its free end a crank arm 17 extending longitudinally with respect to the track 3, and the said crank arm 17 has its outer end connected with the upper end of the operating rod 9 by means of a bent link member 18. This link 18 forms the pivotal connection between the upper end ofthe operating rod 9 and the crank arm 17, so that upon the downward movement of the operating rod 9 the crank arm 17 will be moved downward owing to said connection, and the shaft 15 will consequently be rocked, for a purpose to be hereinafter more fully set forth.

The casing 6 that supports the braking mechanism of this invention, is formed substantially right angular triangular shape, having its longest flat side adapted to engage and be securely attached to the bottom of the step 2. This casing 6 is formed in two parts, that is one of its sides which is removably attached thereto, so that should any of the parts of the brake become worn or broken, the casing may be easily accessible to entrance to repair or replace the same, and the other portion of the said casing is pro- 'vided with laterally extending flanges 20 at their upper rear ends, so that said casing may be secured to the bottom of the step 2 as has been hereinbefore stated. This fastening means is carried out by means of bolts 21 which extend upwardly through the step 2 as clearly shown in Fig. 2 of the drawings and firmly and securely hold the casing attached thereto.

The top of the casing (3 is provided adj acent the smaller end of the same, with an opening 22 therein which is protected by an upwardly extending reinforcing flange 23. Extending upwardly through this opening 22 in the top of the casing 6 is a shaft 21, which is adapted to support at its upper end a brake shoe 25. This brake shoe 25 has formed in its lower end a socket 26 into which the upper end of the shaft 24 projects, and the said shoe is slidably adjustable on the shaft by means of a set screw 27. This brake shoe 25 is so spaced as to be normally positioned into engagement with the lower surface of the track 3 by a means to be hereinafter more fully set forth. The brake shoe 25 has its upper surface lined with rubber or any other suitable material such as designated by the numeral 28, so that the same will firmly and securely engage the lower surface of the said track.

The lower end of the shaft 241 is bifurcated as shown at 29, and has positioned therebetween a lever 30, which is pivoted at one of its ends 31 to the smaller end of the said casing as shown at 32. The other end of this lever which is designated by the numeral 33 is apertured and is adapted to receive one end of a coil spring 34, with its other end secured to a transversely extending pin 35 adjacent the top of the casing. This pivoted lever 30 which is adapted to swing within the casing 6, has a guide for the same, formed by two laterally extending ribs projecting inwardly from either inner wall of the casing as shown at 36. These ribs form a guide for the swinging movement of the lever, and the lower end of the same forms a notch in which the end of the lever is adapted to rest when the same is disengaged from the coil spring 34:.

The bifurcated lower end of the shaft 24: is positioned at each side of the lever 30 adj acent the pivoted end 31 of the same, and the said portion of the lever that is surrounded by the bifurcated end of the shaft has formed therein a slot 37, through which is adapted to be positioned a pin 38 that pivotally and slidably connects the end of the shaft 24 with the lever 30 at this point. It will be obvious from the above positioning that owing to the fact that the lever 30 is pivoted at its end adjacent where the same is connected with the lower end of the shaft 34%, and owing to the fact that the other end of the lever is under a constant upward pull through'the agency of the coiled spring 341, the brake shoe 25 on the upper end of the shaft 24 will consequently be held firmly and securely against the lower surface of the track 3, which is in applied position.

The casing 6 is provided at a point adja cent the upper end of the same, and intermediate its ends with a pair of alining apertures 39, through which one end of the rock shaft 15 is adapted to be positioned.

The rock shaft 15 that is positioned transversely across the casing 6 has mounted thereon a cam 10, which has its lower face engaged with a portion of the upper side of the pivoted lever 30. By this positioning it will be obvious that upon the rocking of the shaft 15 the cam 40 will be moved downwardly which will force the pivoted lever 30 downwardly against the tension of the coiled spring 34: and owing to the fact that the lower end of the shaft 24 is connected to the said lever, the brake shoe 25 on the upper end of the said shaft will be disconnected or retracted from engagement with the track 3 and the brake will be released.

It will be obvious from the foregoing description that when the parts of this device are normally positioned as shown more earticularly in Figs. 1 and 3 of the drawings the brake shoe 25, owing to the constant upward pull of the coil spring 3 1 on the pivoted lever 30 which is connectedwith the shaft 24c that supports the said brake shoe, will be normally positioned into engagement with the track 3, so that the ladder 1 will ordinarily be firmly and securely locked at the position it is placed in along the said tracl. When it is desired to retract the brake from engagement with the track 3, so that the ladder may be moved to another position, the handle 10 of the operating rod 9 is grasped and the said rod is moved downwardly a short distance, whereby owing to the link connection between the crank arm 17 and the upper end of the operating rod 9, the rock shaft 15 will be rocked a predetermined distance. This rocking of the shaft 15 will move the cam 4L0 which is secured thereon in the casing 6, downwardly whereby the pivoted lever 30 will be moved downwardly agalnst the tension of the coil spring 34, which will move the shaft 2 f downwardly and conse quently disengage the brake shoe 25 which is on the upper end of the shaft 24 from the track 3.

When the brake of the ladder has been retracted as above described, the same may be moved easily along the track 3 to any desired position and when the said position has been reached the operator merely has to release the operating rod 9 whereby the expansion of the coil spring 13 which is positioned between the bars 11 and 12 of the bracket 7 that supports the said rod, will move the same upwardly to its normal position as has been heretofore particularly described. Automatic movement of the rod 9 to its normal position will throw the link 18 which pivotally connects the upper end of the same with the crank arm 17, and will rock the shaft 15 in the opposite direction. This movement of the shaft 15 will return the cam 40 to its normal position as shown in Fig. 3 of the drawings, whereupon the coil spring 34 in the casing will pull the pivoted lever 30 upward and consequently the shaft 24 will be moved upward so that the brake shoe 25 will again firmly and securely engage the track 3. This movement of the brake to applied position is automatic when the operator of the same releases the operating rod 5) so that the latter will always firmly and securely be held in the position in which it is placed.

The use of an improved brake of this character 011 movable ladders prevents any chance of the ladder sliding from under the workmen while they are engaged in removing packages or bundles from the shelves with one or both hands and the resulting injuries incidental thereto. lhis improved brake may be applied to any rolling ladders, which are supported either by an overhanging track, or the said brake may be reversed and applied to a track that runs along the floor beneath the ladder. This improved brake when applied to ladders of this character will obviously prevent any sliding movement of the same except at the will of the user.

From the foregoing description of the construction of my improved locking device for movable ladders the manner of applying the same to use and the operation thereof will be readily understood and it will be seen that I have provided a simple, in-

expensive and eiiicient means for carrying out the objects of this invention.

I claim as my invention:

1. A device of the class described comprising a member movable along a track, a spring actuated normally applied brake centrally positioned between the side bars of said member engaging the track, brake releasing means connected therewith and extending to one side of said member, and a hand operating mechanism disposed on the side of said member adjacent the brake operating means and connected therewith to release the brake for movement of said member.

2. A device of the class described comprising a member movable along a track, a casing on said member disposed beneath the track, a brake engaging track having its lower end positioned in the casing, a spring actuated lever in said casing connected with the said brake to hold the same normally applied, and means to retract the said brake.

3. A device of the class described comprising a member movable along a track, a casing on said member disposed beneath the track, a shaft projecting upwardly from said casing having a brake shoe adapted to engage the track on its upper end, a spring actuated pivoted lever engaging the other end of the shaft in the casing to hold the brake normally applied, and means to re tract the said brake.

4. A device of the class described comprising a member movable along a track, a casing on said member disposed longitudinally beneath the track, a shaft projecting upwardly from one end of the casing, a brake shoe adapted to engage the brake adjustably mounted on the upper end of said shaft, a pivoted lever in the casing engaging the other end of the shaft, a coiled spring connected with said link to hold the brake normally applied, and means to retract the said brake.

5. A device of the class described comprising a member movable along a track, a substantially triangular shaped casing on said member disposed longitudinally be neath the track, a shaft projecting upwardly from one end of the casing, a brake shoe adapted to engage the track adjustably mounted on the upper end of said shaft, a lever in said casing pivoted at one end in the end of the casing adjacent the shaft and pivotally connected therewith, a coiled spring adjacent the top of the casing secured to the free end of the lever to exert a constant upward pull on the same to hold the brake normally applied, a guide for said lever in the casing, and means to retract the member projecting upwardly from said casing and engaging the said track, a spring actuated pivoted lever in the casing connected to said brake and adapted to hold the brake normally applied, a cam positioned in said casing engaging a portion of the top of the lever, and means to rock the same cam to move the lever downwardly to release the brake.

7. A device of the class described comprising a member movable along a track, a casing disposed longitudinally beneath said track and centrally between the side bars of the member, a brake member projecting upwardly from said casing and engaging said track, a spring actuated pivoted lever in the casing connected to said brake and adapted to hold the brake normally ap plied, a cam positioned in said casing engaging a portion of the top of said lever, said cam mounted on a rock shaft projecting transversely through the casing and extending to a point adjacent one side bar of said member, and means on said side bar .of the member to rock said shaft to release the brake.

8. A device of the class described comprising a member movable along a track, a casing on said member supporting a brake normally applied to said track, means in said casing to retract said brake, a rock shaft connected with said means, a crank arm at the free end of said shaft, and a rod to permit said crank arm to rock the said shaft and actuate said brake retracting means.

9. A device of the class described comprising a member movable along a track, a casing on said member supporting a spring actuated normally applied brake, means in said casing to retract the brake, a rock shaft connected with said means and projecting from the casing, a crank arm on the free end of said shaft, a hand operated slidable rod connected to said crank arm at its upper end, and means on said rod to automatically retract the same to its normal position when the rod is moved to release the brake.

10. A device of the class described comprising a member movable along a track, a casing on said member disposed centrally between the side bars of the same and supported thereon, a spring actuated normally applied brake, means in said casing to retract the brake, a rock shaft connected with said means extending transversely through the casing and laterally therefrom to a point adjacent one of the side bars of the member, brackets on the said side bar, a crank arm on the free end of the shaft, and an operating rod longitudinally slidable in said brackets connected with the said arm.

11. A device of the class described comprising a member movable along a track, a casing on said member disposed centrally between the side bars thereof, a spring actuated normally applied brake, means in said casing to retract the brake, a rock shaft connected with said means extending transversely through the casing and laterally therefrom to a point adjacent one of the side bars of the member, brackets on said side bar, a crank arm on the free end of the shaft, a rod, a link connecting said rod and crank arm, and a coiled spring surrounding the rod in one of said brackets adapted to be contracted upon operative movement of the rod and to return said rod to normal position when it is released.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

MORGAN EDWIN HOWVELLS. WVitnesses:

A. F. TURNER,

GEO. L. Drr'ro.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, I). G. 

